text: In 1939, Wendell H. Furry proposed the idea of the Majorana nature of the neutrino, which was associated with beta decays. Furry stated the transition probability to even be higher for neutrinoless double beta decay. It was the first idea proposed to search for the violation of lepton number conservation. It has, since then, drawn attention to it for being useful to study the nature of neutrinos (see quote).
  The Italian physicist Ettore Majorana first introduced the concept of a particle being its own antiparticle. Particles' nature was subsequently named after him as Majorana particles. Neutrinoless double beta decay is one method to search for the possible Majorana nature of neutrinos.